The related applications describe and claim aspects of a power supply controller which can be used for controlling a plurality of isolating and/or non-isolating power supplies, such as switch mode power supplies or DC power converters, and linear voltage regulators, for providing controlled electrical power to loads. For example, the power supplies may provide different supply voltages to various electrical circuits on a circuit card on which the power supply controller is also provided. As described in the related applications, the power supply controller has six converter state machines (CSMs), one for each of up to six controlled power supplies, and an input state machine (ISM) for an input or supply voltage for the controlled power supplies.
A primary aspect of the control of the power supplies relates to their sequencing in accordance with conditions monitored by the power supply controller. Sequencing refers to an order in which, and parameters in dependence upon which, the power supplies are enabled or started up in a power-up process, disabled or shut down in a normal power-down process, and/or disabled or shut-down in a fault situation. The monitored conditions include, for example, the input voltage and the output voltages produced by the respective power supplies. For example, enabling of each individual controlled power supply on power-up of the circuit card can be dependent upon the input voltage, or upon a monitored output voltage of a prior-enabled power supply, exceeding a threshold voltage.
The related applications by D. Brown et al. disclose arrangements of controlled power supplies that can provide relatively arbitrary sequence topologies, and that allow for a location of each controlled power supply on either a main circuit board or a daughter board. As described in these applications, various configuration registers are provided in the power supply controller to identify the presence and locations of the controlled power supplies and their sequencing for power-up, normal shut-down, and shut-down in a fault situation.
In addition to this information, it is desirable to be able to vary, and it is therefore necessary to specify for desired operation of the power supply controller, a large amount of other configuration information relating to the controlled power supplies and their sequencing.
By way of example, such other information can include, for each controlled power supply, under- and over-voltage thresholds and associated time periods for triggering warnings and detecting fault conditions in operation of the controlled power supply, a mask time period for start-up to be completed before under-voltage monitoring takes effect, a start-up voltage threshold which must be exceeded to trigger a subsequent CSM in the power-up sequence of the controlled power supplies, a restart voltage threshold below which the monitored voltage must fall before a power-up sequence is initiated following a shut-down of the controlled power supplies, voltage parameters for adjustment or trimming of the controlled power supply output voltages, and time delay periods associated with the power-up, normal shut-down, and fault shut-down sequences.
Such other information can further include a threshold voltage and related period which must be exceeded by the input voltage for a power-up sequence of the controlled power supplies to begin, and information related to the use of general purpose input/output (GPIO) pins of the power supply controller.
All of this and any other desired information for operation of the power supply controller, collectively referred to herein as configuration information, must be correctly set up for operation of the power supply controller. For example, the configuration information is stored in a non-volatile random access memory (NVRAM) of the power supply controller, and is downloaded from the NVRAM to registers of the power supply controller on power-up of the power supply controller.
While such a power supply controller is very versatile, it can be seen that its configuration information is relatively complex. Voltage thresholds and time delays such as those identified above, especially those relating to power supply sequencing for power-up and shut-down, must be correctly set for operation of the power system; if even one of the registers for this configuration information is set incorrectly the power system may be rendered inoperable. Furthermore, the configuration of the power supply controller may be by power system designers who have previously used only analog power system control circuits and who are not familiar with a configurable power supply controller such as described above.
Accordingly, there is a need to facilitate such configuration of a power supply controller.